A main wing of an UAV may comprise a plurality of segments that can be assembled. As shown in FIGS. 1a to 1c, currently, the main wing of an UAV comprises a centre wing 101 attached to the fuselage of the aircraft, and a pair of outboard wings 103 that can be attached to the outboard edges 102 of the centre wing 101.
Each outboard edge 102 of the centre wing 101 has a square shaped slot 105 and a circular slot 107 that are made of metal. An inboard edge 104 of each outboard wing 103 has a square shaped insert 109 and a circular guide 111 that are made of metal. In use, the slot 105 receives the insert 109 and the slot 107 receives the guide 111. A spring lock 110 is provided on one face of the insert 109 to lock the insert 109 to a hole 113 provided on an underside of the of the centre wing 101.
In order to assemble the main wing, the insert 109 and the guide 111 located on the inboard edge 104 of each outboard wing 103 are inserted into the respective slots 105, 107 located on the outboard edge 102 of the centre wing 101. Once positive connection has been established, the spring lock 110 engages and locks onto the hole 113 found on the underside of the centre wing 101.
In order to detach the outboard wings 103 on site, a special tool e.g. a pin is required so as to pierce through the hole 113 on the centre wing 101 and unlock the spring lock 110.
Due to stringent tolerances between the insert 109 and the slot 105, it is difficult to execute a smooth connecting action.
Furthermore, since a portion of the insert 109 is exposed, it is prone to damages which may further deteriorate the engaging or disengaging action of the wings 101, 103.
Since the insert 109 and the slot 105 are the only point of engagement between the centre wing 101 and the outboard wing 101, when the wings 101, 103 are subjected to high launching load, the trailing edge of joint between the centre wing 101 and the outboard wing 103 tends to twist outward in a span wise direction of the wings 101, 103.
Furthermore, the dihedral angle of the outboard wing 103 depends on the molded dihedral angle of both the centre wing 101 and the outboard wing 103. i.e. the angles at which the outboard edges 102 of the centre wing 101 and the inboard edges 104 of the outboard wing 103 are molded, determine the dihedral angle. Therefore, the centre wing 101 and outboard wing 103 are custom built for a particular dihedral angle.
There is thus a need to provide a collapsible wing that seeks to address one or more of the above disadvantages.